Have a 94 600 F2. Changed spark plugs and now the bike dies after 1mi, 10 mi, etc. Fuel filter is clean, lines are clear, gas is good and all connections are ok. Thinking it's a vacuum problem, maybe tank cap related. Any suggestions?

if the bike dies, try to restart it AFTER you open the gas cap( you will need a second key to do this) if the bike starts then it is a venting problem and you probally pinched a vent line.
Hope that works!!

Thanks. Did that; bike started to sputter then ran fine after opening the cap. Can't see any pinched lines -- could it be a vent hole or cap going bad?

When you open the cap there is a hole next to the filler neck and that should be your "breather" which I believe goes to the vent line at the back of the tank under the seat. It has been a few years since I have looked at a F2...if you cant find a pinched line I recommend taking it to a shop..the cap is probally not the problem since the "vent" is below the cap in by the filler neck
It is possible that the fuel petcock could not be "breathing" as well..I know the older CBR Hurricanes had fuel pumps, but the F2 uses gravity and vacumn